First of all, I'm pretty sure the leaked game is a beta, or at least not the final game.
Second, people are so seriously misinformed about the add-ons. They do add a lot of things, not only furniture and careers. Open for Buisiness added buisness micro managing, new types of shops, new skills, new interactions just to name a few...
I understand these might not mean so much for people who aren't into Sims, but for those who are it's a great deal of new things. Thing you don't understand is that it keeps the game fresh and there's so many new things to experiance in those Expansion Packs. Stuff packs however don't add a lot, but it's still better than the Sims 2 store (effing rip-off).
Some other games have expansions as well, Sims is certainly not the only one to do this. The difference between those games and Sims is that in it, there's so much more possibilities, the ideas for it are limitless (though the game has a limit before it gets broken). As a simmer, I do understand the purpose and I do buy them all. I feel sorry for people who don't at least aknowledge it, and move on, instead of criticising without knowing what they're talking about. Oh and as you well know, I also play games like Zelda, Mario, Star Ocean... I don't feel less of a gamer because I play Sims. It's not as casual as you'd like to think.
Third, EA probably isn't worried at all. Some people who pirated are going to buy the game afterwards (I know a great deal of people who will) plus even if they didn't, the game will still sell a lot.